Парс Каналов

Помогите сделать так, чтобы по моему запросы парсились все каналы, который выдаёт ютуб
Вот код:

using Fizzler.Systems.HtmlAgilityPack;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Windows.Forms;



namespace Boil
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

public void label1_Click(object sender, EventArgs e)
{

}

public void textBox1_TextChanged(object sender, EventArgs e)
{

}

public void button1_Click(object sender, EventArgs e)
{
Start();
}
public void richTextBox1_TextChanged(object sender, EventArgs e)
{

}






public void Start()
{
WebClient web = new WebClient();
string txt = textBox1.Text;
string[] hui = SortTextForReq(txt);
string LoadString = "https://www.youtube.com/results?search_query=";
for (int i = 0; i < hui.Length; i++)
{
LoadString += hui[i] + "+";
}
richTextBox1.AppendText(LoadString + " ");
string resp = web.DownloadString(LoadString);
File.WriteAllText("Query.html", resp, Encoding.UTF8);
Process.Start("Query.html");



HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(resp);

string pars = doc.DocumentNode.QuerySelector("ytd-app").InnerHtml;

foreach (var item in doc.DocumentNode.QuerySelectorAll("a#yt-simple-endpoint style-scope yt-formatted-string.spellcheck.href")) //в этой строке пытаюсь найти каналы, но не работает
{
richTextBox1.AppendText(item.InnerText + " ");
}


}
public static string[] SortTextForReq(string text)
{
string[] words = text.Split(' ');

int counter = 0;

//for (int i = 0; i < words.Length; i++)
//{
// if (words[i] != null || words[i] != "")
// {
// counter++;
// }
//}

//string[] sortWords = new string[counter];
//int iter = 0;

//for (int i = 0; i < words.Length; i++)
//{
// if (words[i] != "")
// {
// sortWords[iter] = words[i];
// iter++;
// }
// else
// {
// continue;
// }
//}
return words;
}


}
}

Код

using Fizzler.Systems.HtmlAgilityPack;

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Diagnostics;

using System.Drawing;

using System.IO;

using System.Linq;

using System.Net;

using System.Text;

using System.Threading.Tasks;

using System.Web;

using System.Windows.Forms;







namespace Boil

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }



        public void label1_Click(object sender, EventArgs e)

        {

           

        }



        public void textBox1_TextChanged(object sender, EventArgs e)

        {

           

        }



        public  void button1_Click(object sender, EventArgs e)

        {

            Start();

        }

        public void richTextBox1_TextChanged(object sender, EventArgs e)

        {



        }













        public void Start()

        {

            WebClient web = new WebClient();

            string txt = textBox1.Text;

            string[] hui = SortTextForReq(txt);

            string LoadString = "https://www.youtube.com/results?search_query=";

            for (int i = 0; i < hui.Length; i++)

            {

                LoadString += hui[i] + "+";

            }

            richTextBox1.AppendText(LoadString + " ");

            string resp = web.DownloadString(LoadString);

            File.WriteAllText("Query.html", resp, Encoding.UTF8);

            Process.Start("Query.html");







            HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();

            doc.LoadHtml(resp);



            string pars = doc.DocumentNode.QuerySelector("ytd-app").InnerHtml;



            foreach (var item in doc.DocumentNode.QuerySelectorAll("a#yt-simple-endpoint style-scope yt-formatted-string.spellcheck.href")) //в этой строке пытаюсь найти каналы, но не работает

            {

                richTextBox1.AppendText(item.InnerText + " ");

            }

           



        }

        public static string[] SortTextForReq(string text)

        {

            string[] words = text.Split(' ');

           

            int counter = 0;



            //for (int i = 0; i < words.Length; i++)

            //{

            //    if (words[i] != null || words[i] != "")

            //    {

            //        counter++;   

            //    }

            //}



            //string[] sortWords = new string[counter];

            //int iter = 0;



            //for (int i = 0; i < words.Length; i++)

            //{

            //    if (words[i] != "")

            //    {

            //        sortWords[iter] = words[i];

            //        iter++;

            //    }

            //    else

            //    {

            //        continue;

            //    }

            //}

            return words;

        }



       

    }

}